360 wheels on 348 ?

Length is determined by the wheel, not the car. Get 20 360 bolts here: https://www.hillengineering.co.uk/wheel-bolts/bolts-by-model/slwb-01

 

What model 348 do you have? If you have 55mn bolts all around (high offset rear wheels) then they should work. 360 bolts are slightly shorter — 52mm shank iirc — than your 55mm 348 bolts, but I doubt that 3mm difference will matter.

 

Assuming you have factory wheels I think you’ll be fine with your 55mm bolts.

 

If you machine down the rear 360 wheels 17mm, you then use 308 wheel bolts IIRC.

 

Other info. Some people like the 1970s crager SS rear wheel stick out look. And that is perfectly fine for them.

https://www.ferrarichat.com/forum/threads/348-355-360-wheel-offset.600577/

 

It is a personal preference.... but in my opinion, the rear wheels need to be machined down to avoid looking like (as @Ferrarium ) eloquently put it "a 1970's Crager SS"

 

This is the best looking 360 wheel fitment I've seen: https://www.ferrarichat.com/forum/posts/139189146/

The 355 bumpers don't hurt and look surprisingly at home...